Field of the Invention
The present invention relates to an oligonucleotide and method for detecting target DNA in a sample.
Description of Prior Art
Recently, some noble-metal nanoparticles using DNA as a template for fluorescent metal nanoparticles (NPs) or nanoclusters (NCs) through the binding of metal ions on the DNA and subsequent chemical reduction of the DNA-complexed metal ions. Therefore, DNA-templated fluorescent metal NPs or NCs show great potential as fluorescent probes for biochemical applications due to their advantages of ultrafine size, low toxicity, good biocompatibility, outstanding photophysical properties, as well as facile integration with nucleic acid-based target-recognition abilities and signal amplification mechanisms.
Compared with other existing fluorescent metal NPs, DNA-templated copper NPs (CuNPs), including random double-stranded DNA-templated CuNPs (dsDNA-CuNPs) and poly(thymine)-templated CuNPs (poly T-CuNPs) were reported by Mokhir et al. and Wang et al., respectively. Its formation might be resulted from the high-affinity clustering of Cu0, which is formed through chemical reactions between Cu2+ and the reducing agent in solution, on DNA scaffolds. Furthermore, the synthesis of CuNPs is highly efficient, simple, and rapid (about 5 min at room temperature), thus laying a substantial foundation for their widespread applications in biosensing.